One thing that Abobe did well - they added a Composite tag to their SVG
output. This is something I would like to suggest the SVG working
comitee consider adding to the spec. Essentially, it lets you do
brighten, darken, multiply, screen and all those useful Abode overlays
without having to have all the overhead of filters. If you want to
apply a pixel tweaking effect that could be described by geomerty (ie,
have a circular area fade to blue, add shadows that tint rather than
obscure, brighten a region defined by a path, or make a rectangular
region monochrome, a Composite is a great, easy to implment and memory
saving technique over filters.
Mark McKay